Hi!

While rebuilding packages against python 3.15 we found that cython
produces some errors when used against it. Some of this caught by the
autopkgtest
(https://debusine.debian.net/debian/r-python-python3.15/work-request/972899/)
.

I'm attaching a debdiff that adds the upstream fixes related to python
3.15, these fix the build against python 3.15, these fixes are in the
history of the upcoming 3.3.0 release.

I'll also send a merge request for this changes to salsa which might be
easier to work with depending on your workflow.

Happy hacking,

We believe that the bug you reported is fixed in the latest version of
cython, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1143845@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Boyuan Yang <byang@debian.org> (supplier of updated cython package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sat, 24 Oct 2026 12:34:39 -0400
Source: cython
Architecture: source
Version: 3.1.6+dfsg-4
Distribution: unstable
Urgency: medium
Maintainer: Debian Python Team <team+python@tracker.debian.org>
Changed-By: Boyuan Yang <byang@debian.org>
Closes: 1143845
Changes:
 cython (3.1.6+dfsg-4) unstable; urgency=medium
 .
   * Team upload.
   * Backport Python 3.15 compatibility fixes. (Closes: #1143845)
   * debian/patches/46ee38dd0ed8d5fe90fb31690e6e9a39ba1e2a4b.patch: Adapt
     string formatting tests to Python 3.15 error messages.
   * debian/patches/736a2c3603363b64fc7639ba050982d9609b7750.patch:
     Recognize lazy-import builtins from Python 3.15.
   * debian/patches/42d13596c8a531e83a337e014fa7ef2f4d162ded.patch:
     Recognize frozendict from Python 3.15.
   * debian/patches/414ef78348a6aa1f3abd310ded388a10348b67c9.patch:
     Recognize sentinel from Python 3.15 and avoid caching its new
     builtins on older Python versions.
   * debian/patches/a470483da2274ca272e70280fa27b5f7e90c9e09.patch: Adapt
     array declarations to the Python 3.15 layout.
   * debian/patches/42830b85c8ae7489dac9d143f521e392d966d8c8.patch:
     Preserve negative cpdef enum values on Python 3.15.
Checksums-Sha1:
 1c744828f19b6174c11b8c50438bccf6c64592ea 3039 cython_3.1.6+dfsg-4.dsc
 87eeb02e973b5d62adbeaa3461710efe10ed0ec8 2557448 cython_3.1.6+dfsg.orig.tar.xz
 3e6d0b160309c1ee9ae3c41dba510da0f5a26d5c 33328 cython_3.1.6+dfsg-4.debian.tar.xz
 d7762672d04bbc1ff7b9eaca6eed2b246d9e33ab 9508 cython_3.1.6+dfsg-4_amd64.buildinfo
Checksums-Sha256:
 5a9742063a37eeaf16e812cdb16d69b3bfb3224ab55a8512edfd297dda4445ef 3039 cython_3.1.6+dfsg-4.dsc
 9de56310c9a51b1de840ae817899cd287d72e8b9a42da529044fbfd7334fa77c 2557448 cython_3.1.6+dfsg.orig.tar.xz
 28f18803330e1d69b6f98320a472c0a311ea098da4ebf8a6b3c23afbb3ca04e3 33328 cython_3.1.6+dfsg-4.debian.tar.xz
 c2b17b0a8f9d9f863354efb94ace8520c41f05c9e4310db825692e0486daa84d 9508 cython_3.1.6+dfsg-4_amd64.buildinfo
Files:
 05aa4ab687435e7c60f9531b330ea4f7 3039 python optional cython_3.1.6+dfsg-4.dsc
 c47c94c4af6f7b62fdf1bd43acdd5c28 2557448 python optional cython_3.1.6+dfsg.orig.tar.xz
 946675eeb5e03b723b4cd3017a7f4ee4 33328 python optional cython_3.1.6+dfsg-4.debian.tar.xz
 0dbbc394215fcb525fd858ef46e8ecc5 9508 python optional cython_3.1.6+dfsg-4_amd64.buildinfo
-----BEGIN PGP SIGNATURE-----
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=P8Nr
-----END PGP SIGNATURE-----